Wednesday, December 31, 2014

What does Percent Not Converging Mean in SWMM5?

"SWMM 5's Routing Time Step Summary is your window into the model's heart, offering valuable insights with each pulse of data 🌟📈:

  • Minimum Time Step: How swiftly the model can adapt to change, with a record speed of just 0.52 seconds! ⏱️✨
  • Average Time Step: Balancing precision and performance, the model averages a comfortable 8.76 seconds. 🔄
  • Maximum Time Step: Never missing a beat, the maximum cap is a steady 10.00 seconds. ⏳
  • Percent in Steady State: A tranquil sea with 0.00% time in a steady state, reflecting constant motion. 🌊
  • Average Iterations per Step: A modest 2.14 iterations, showcasing the model's efficiency. 🔄
  • Percent Not Converging: Only 1.69% of the time, the model's predictions and reality don't quite align. 🛠️

Figure 1 illuminates the maximum trials per time step. This number reflects the model's persistence in seeking convergence during dynamic wave routing. 🌐🔍

Convergence in the Dynamic Wave Solution:

  • The dance of calculation continues until the steps match the maximum number of trials. 🕺💃
  • At each time step, the flows and depths are reassessed. If all nodes agree within the head tolerance, the iteration halts. 👍
  • A single non-convergent node increments the Non-Converge Count, a rare occurrence. 📊
  • Efficiency tip: Links that can be bypassed are noted, speeding up the process when dynamic wave calculations are unnecessary. 🏎️💨

With SWMM 5, you're not just running a model; you're conducting an orchestra of data where each note is a time step, each rest a chance to converge, and the symphony is the fluid mechanics of urban water systems. 🎼🌆"

  Routing Time Step Summary
  Minimum Time Step           :     0.52 sec  
  Average Time Step           :     8.76 sec
  Maximum Time Step           :    10.00 sec
  Percent in Steady State     :     0.00
  Average Iterations per Step :     2.14
  Percent Not Converging      :     1.69

Figure 1.  Maximum number of trials per time step

In the dynamic world of SWMM 5, the Routing Time Step Summary serves as a crucial indicator of model stability and efficiency 🌐🔧. Here's a snapshot:

  • Percent Non-Converging: This is the fraction of time when at least one element in the model's intricate network didn't align within the set number of trials per step. It's the ratio of the total non-convergent steps to the overall number of steps taken during the simulation 🔍💡.

  • Dynamic Wave Solution Mechanics: Like a conductor leading an ensemble, the program meticulously iterates until the number of steps aligns with the maximum trials allowed. Each step is a note, each calculation a beat 🎶🧮.

  • Convergence: It's a delicate balance. If all node depths settle within the accepted variance (below the head tolerance) after more than one step, the model ceases iterations. Harmony is achieved ✅🔄.

  • Non-Convergence: However, should even a single node remain unresolved, the Non-Converge Count ticks up, a rare but noted event in the symphony of simulation 🚦📊.

  • Efficiency: Not every link needs a detailed calculation at each step. By identifying which can be bypassed, the program conserves energy, speeding up like a swift current bypassing a tranquil pool 🏎️💨.

Figure 2 likely illustrates this concept further, capturing the essence of a model that is both robust and refined. By understanding these dynamics, you can ensure a smoother, more accurate simulation, leading to more reliable predictions and planning in urban water systems 🌟🌊.

Figure 2.  Link Bypass is based on the Upstream and Downstream Nodes

    // --- keep iterating until convergence 
    while ( Steps < MaxTrials )
        // --- execute a routing step & check for nodal convergence
   converged = findNodeDepths(tStep);
        if ( Steps > 1 )
            if ( converged ) break;

            // --- check if link calculations can be skipped in next step
    if ( !converged ) NonConvergeCount++;

    //  --- identify any capacity-limited conduits

    return Steps;

Tuesday, December 30, 2014

How to Make a Trapezoidal Inflow Time Series in InfoSWMM

You can make a Trapezoidal shaped Time Series in InfoSWMM by using the following steps:
  1. .       Use the Inflow Icon at a Node in the Attribute Browser
  2. .       Use either an Inflow Time series with date/time/value or
  3. .       A baseline flow value with a pattern
  4. .       The time series comprise a Date that matches your simulation time period
  5. .       A hour:minute:second Time value in the Time Series Table
  6. .       A flow unit with the units used in the General Tab of Run Manager
  7. .       This time series is entered in the Attribute Browser under Time Series in the Operation Tab
How to Make An Inflow Time Series at a Node in InfoSWMM

Sunday, December 28, 2014

The EPA SWMM 5 code and the various versions of Visual Studio

The EPA SWMM 5 code and the various versions of Visual Studio. If you have multiple versions of Visual Studio on your computer you might have toolset issues.  Visual Studio 2010 and 2012 are for Windows 7, Visual Studio 2013 is for Windows 8

Visual Studio 2012 uses the v11 toolset

Visual Studio 2013 uses the v12 toolset

Visual Studio Configuration Properties

Thursday, December 25, 2014

How to Make Scatter Graphs in InfoSWMM and H2OMap SWMM

How to Make Scatter Graphs in InfoSWMM and H2OMap SWMM

Scatter graphs of velocity on the X axis and depth on the Y axis are important to help understand the reason for flow/depth relationships in flow surveys.  You can make a scatter graph in InfoSWMM by plotting the link flow and the by clicking on the Report button.  A right mouse click will bring up the Data Scatter Plot option. The column on the left of the selected columns will be the X Axis column of data. The column on the right will be the Y Axis column of data.  The default is depth followed by velocity. The order variables can be changed by using the Format Icon (bullet 1) followed by the Scatter Plot selection of velocity/depth (see Figure 1 for an example).  Figure 2 shows how to make a Log/Log Scatter Graph in InfoSWMM using the Properties Icon.

Figure 1.  The Basic Velocity vs Depth Scatter Graph in InfoSWMM

Figure 2.  The Log/Log Options for a Scatter Graph.

AI Rivers of Wisdom about ICM SWMM

Here's the text "Rivers of Wisdom" formatted with one sentence per line: [Verse 1] 🌊 Beneath the ancient oak, where shadows p...